JP2010014597A - Mobile contact inspection apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a mobile contact inspection apparatus for reducing inspection time and improving inspection efficiency. <P>SOLUTION: The mobile contact inspection apparatus includes a plurality of movable probes and measures electrical characteristics at a plurality of places in an inspection target. The plurality of movable probes includes one direct coupling type movable probe and other switching type movable probes. Furthermore, the mobile contact inspection apparatus includes: an XYZ drive section for supporting the respective movable probes for accurate positioning and bringing into contact with the inspection target; a switch section for electrically and mutually short-circuiting and selectively connecting the plurality of switching type movable probes; and a control unit for simultaneously bringing the direct coupling type movable probe and switching type movable probe into contact with a plurality of places in the inspection target, determining that a fault has occurred when the synthesis value of electrical characteristics detected by each switching type movable probe short-circuited via the switch section deviates from an expectation value, and selectively connecting each movable probe for locating a faulty place by controlling the switch section. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a movable contact inspection apparatus for inspecting electrical characteristics such as insulation resistance between wirings of a printed wiring board.

  When a printed wiring board or the like is used to inspect an insulation resistance between nets (wirings) as electrical characteristics, a movable contact inspection device is used. There is a flying prober as an example of such a movable contact inspection apparatus, and the following is an example of an inspection method using this flying prober.

  As shown in FIG. 2, in the inspection method using this flying prober, when measuring the insulation resistance between the nets A, B, C, and D, the two movable probes are brought into contact with the two nets to be measured for insulation. It measures resistance. Specifically, first, as the first inspection, two movable probes are brought into contact between the two nets A and B, and the insulation resistance is measured. As the second inspection, the two movable probes are connected between the two nets A and C. Insulation resistance was measured in contact with each other, and as the third inspection, two movable probes were brought into contact between two nets AD to measure insulation resistance. As described above, when there are a plurality of nets to be inspected for insulation, the target nets are measured and inspected one by one. When there were n sets of nets to be inspected, the inspection was performed n times. However, such conventional inspection methods have poor inspection efficiency.

There exists invention of patent document 1 as a means to solve such a problem. In Patent Document 1, a predetermined DC voltage is applied between wirings to be inspected, and a resistance value between patterns is calculated from a current value and a voltage value at that time. In addition, it has a calculation function that measures whether or not a spark is generated at the time of an insulation test, and sets a failure even if the resistance value is good when a spark occurs. At the time of measurement, a switch circuit has a function of connecting each net to a maximum of 4 nets and inspecting in order, thereby shortening the inspection time.
Japanese Patent No. 3546046

  By the way, when the four nets are inspected sequentially by the switch circuit at the time of measurement, it is possible to reduce the inspection time, but it is not a significant reduction.

  In particular, the number of nets has increased with the recent increase in circuit density. However, when each net is inspected in turn, there is a problem that the inspection time significantly increases and the inspection efficiency deteriorates.

  An object of the present invention is to provide a movable contact inspection apparatus that solves these problems of the prior art and shortens inspection time and improves inspection efficiency.

  The present invention has been made in view of the above-described problems, and a movable contact inspection apparatus according to the present invention has a plurality of movable probes and measures the electrical characteristics of a plurality of locations of an inspection object. In the apparatus, the plurality of movable probes includes at least one direct-coupled movable probe and another switching movable probe, and each of the movable probes is accurately positioned by supporting each movable probe. An XYZ drive unit that is brought into contact with the switch, a switch unit that electrically short-circuits and selectively connects the plurality of switchable movable probes, and the direct-coupled movable probe and the switchable movable probe. From the expected value, the combined value of the electrical characteristics detected by each switching type movable probe that is simultaneously contacted at multiple locations and short-circuited via the switch section It is determined that abnormality if they are, the switch unit selectively connecting each movable probe to control, characterized by comprising a control device for performing specific abnormal point. When the control device determines that the combined value of the electrical characteristics is out of the expected value and is abnormal, the switch unit is controlled to connect each movable probe one by one to identify the abnormal location. desirable. Or, by controlling the switch unit to connect a plurality of movable probes one by one to roughly identify an abnormal location, and then specify the abnormal location by narrowing down the range for identifying the abnormal location in stages. desirable.

  In order to simultaneously determine a plurality of electrical characteristics by determining whether or not the combined value of the electrical characteristics detected by each switching type movable probe short-circuited via the switch unit deviates from the expected value, Inspection time can be greatly shortened and inspection efficiency can be improved.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The movable contact inspection apparatus according to the present embodiment is an inspection apparatus that includes a plurality of movable probes, moves each movable probe, and simultaneously contacts a plurality of points to simultaneously measure electrical characteristics at a plurality of locations. Various devices can be used as the movable contact inspection device. At least all inspection apparatuses having the configuration of FIG. 1 to be described later can be used. Here, a flying prober will be described as an example. This flying prober has a plurality of movable probes and is a device for inspecting electrical characteristics between two points. For example, in a printed circuit board having n nets, electrical characteristics (here, insulation resistance) between two points between this net and the other n-1 nets with respect to one net. Inspect. That is, the insulation resistance between two points of the n-1 set of nets is inspected.

  In the flying prober according to the present invention, a plurality of movable probes move at a high speed on the upper side of the printed circuit board installed on the inspection table, and each of the electrodes (contact points) of each net (a group of wiring) on the printed circuit board. Check by contact. In order to inspect each one of a large number of nets formed on the printed circuit board, a plurality of movable probes move on the printed circuit board at a high speed at the same time, and contact each net contact point for inspection. Each movable probe contacts the contact point of each net for a very short time and inspects one after another. A schematic configuration of the flying prober will be described based on the functional block diagram of FIG.

  The illustrated flying prober mainly includes four movable probes 1, an XYZ driving unit 2 that drives each movable probe 1, a switch unit 3 that electrically and selectively connects each movable probe 1, and the whole. And a control device 4 to be controlled.

  The movable probe 1 is a contact that is supported so as to be individually movable so as to directly contact the contact point of each net 6. The movable probe 1 is supported by the XYZ driving unit 2 and moved to an arbitrary position. The four movable probes 1 are divided into two types. One is a direct-coupled movable probe 1A, and the other three are switching movable probes 1B, 1C, and 1D. The direct connection type movable probe 1A is directly connected to the control device 4, and the switching type movable probes 1B, 1C, 1D are connected to the control device 4 via the switch unit 3. Thereby, resistance is detected with the combination of movable probe 1A-1B, 1A-1C, 1A-1D.

  The XYZ driving unit 2 is a device for supporting the movable probe 1 and moving it to an arbitrary position, and accurately positioning and contacting the tip of the movable probe 1 to the contact point of the net 6. The XYZ drive unit 2 includes an X-axis direction drive mechanism (not shown), a Y-axis direction drive mechanism (not shown), and a Z-axis direction drive mechanism (not shown), and supports the movable probe 1. Thus, it can move in the X-axis direction, the Y-axis direction, and the Z-axis direction. Four XYZ driving units 2 are provided to individually support the four movable probes 1. Each XYZ drive unit 2 is connected to the control device 4 and controlled individually.

  The switch unit 3 electrically and selectively selects a combination 1A-1B, 1A-1C, 1A-1D of one direct-coupled movable probe 1A and three switchable movable probes 1B, 1C, 1D. It is a device for connecting to the control device 4. The switch unit 3 includes three switch pieces SW1, SW2, and SW3 that are individually connected to the movable probes 1B, 1C, and 1D. One of the switch pieces SW1, SW2, SW3 is individually connected to the movable probes 1B, 1C, 1D, and the other is short-circuited to each other and connected to an insulation resistance input / output unit 12 (to be described later) of the control device 4. Yes. At this time, each movable probe 1B, 1C, 1D is short-circuited to measure the combined resistance value between A-B, A-C, and A-D. Further, the switch unit 3 is connected to a switch switching control unit 8 described later of the control device 4 so that the three switch pieces SW1, SW2, SW3 are individually controlled to be opened and closed.

  The control device 4 is a device for controlling the movable probe 1, the XYZ drive unit 2, and the switch unit 3. The control device 4 includes a switch switching control unit 8, an XYZ axis drive control unit 9, a display unit 10, an R calculation pass / fail determination unit 11, and an insulation resistance input / output unit 12.

  The switch switching control unit 8 performs switching control of the switch unit 3. Specifically, an abnormal location is specified by turning on one by one from SW1 to SW3 in order. If the number of switches is large, switch with another pattern. For example, half of all switches are switched. That is, all the switches are divided into two, and half of them are inspected to identify the abnormal one. Furthermore, the switch with abnormality is divided into two, and half of the switches are inspected to roughly identify the abnormality. This is repeated, and the range for specifying the abnormal part is narrowed down step by step to finally specify the abnormal part. In addition, divide all switches into three or four or more, and inspect every third or every quarter, or inspect every fifth or more, and step by step the range to identify abnormal points Finally, the abnormal part is identified. It divides | segments suitably according to the number of switches, and test | inspects for every division part.

  The XYZ axis drive control unit 9 is connected to each of the four XYZ drive units 2 and individually controls the X axis direction drive mechanism, the Y axis direction drive mechanism, and the Z axis direction drive mechanism of each XYZ drive unit 2. By the alignment in the XYZ axial directions by this control, the contact point of each net 6 and the tip of the movable probe 1 supported by each XYZ driving unit 2 are accurately aligned. One direct-coupled movable probe 1A and three switching movable probes 1B, 1C, and 1D are simultaneously brought into contact with contact points of the nets 6, respectively.

  The display unit 10 is connected to a monitor (not shown) and displays an image on the monitor. For example, the detected insulation resistance value or the like is displayed on the monitor.

  The R calculation pass / fail determination unit 11 determines whether or not the combined value of the electrical characteristics deviates from the expected value. Here, an insulation resistance is used as an electrical characteristic. A composite resistance value is calculated from the voltage and current taken from the insulation resistance input / output unit 12, and whether the composite resistance value is equal to or greater than a standard value is determined.

  The insulation resistance input / output unit 12 detects a current by applying a set voltage between the direct-coupled movable probe 1A and the switchable movable probes 1B, 1C, and 1D, and the voltage and current between the nets 6 are detected. taking measurement. The measured voltage and current are output to the R calculation pass / fail judgment unit 11.

  Next, specific processing functions in the control device 4 will be described. First, the overall operation will be described based on the timing chart of FIG.

  The probe is brought into contact with each contact point, and SW1 to SW3 are turned ON simultaneously. Next, a set voltage as an inspection signal is applied, and the current and voltage between the nets A-B, A-C, and A-D after the transient current are measured.

  Next, based on the measured current and voltage, the combined resistance between A and B, between A and C, and between A and D is calculated. The current and voltage are measured at an arbitrarily set number of samplings, and the combined resistance between A-B, A-C, and A-D is calculated.

  Next, pass / fail is determined based on the combined resistance value.

  At this time, it is determined whether or not the combined resistance value is equal to or greater than the standard value. If the combined resistance value is equal to or greater than the standard value, the switch portion 3 is selectively switched to identify the defective portion. An operation example of the switch unit 3 will be described with reference to FIGS. 4 and 5 are circuit diagrams schematically showing resistances between the switch unit 3, the control device 4, and each net 6. FIG.

  At the time of measuring the combined resistance, all the three switches (SW1 to SW3) are turned on as shown in FIG.

When the switch part 3 is selectively switched to identify a defective portion, as shown in FIG. 5, one of the three switches (SW1 to SW3) is turned on and the other is turned off. Here, SW1 is turned on and SW2 and 3 are turned off. Next, SW2 and 3 are turned ON in order.

  Next, specific processing functions of the control device 4 will be described with reference to FIG.

  First, an adjacent net is confirmed (step S1), and it is determined whether there is an adjacent net (step S2). When it is determined that there is no adjacent net, that is, when there is one net, measurement is performed at 1: 1 (step S3). When it is determined that there is an adjacent net, the used movable probes 1A, 1B, 1C, and 1D are checked (step S4), and all SW1 to SW3 of the switch unit 3 are turned on (step S5).

  Next, each movable probe 1A, 1B, 1C, 1D is appropriately moved in the XYZ direction by controlling each XYZ driving unit 2, and the tip of the movable probe is brought into contact with the contact point of each net (step S6). .

  Next, a set voltage as an inspection signal is applied between the nets A and B, between A and C, and between A and D, and the voltage and current are measured (step S7). Specifically, the movable probe 1A is brought into contact with the contact point of the net A. In the state where all the SW1 to SW3 of the switch unit 3 are turned ON and the three movable probes 1B, 1C, 1D are short-circuited to each other, the respective contact points of the nets B, C, D to be inspected are simultaneously contacted. Let As a result, the combined voltage and current of the three movable probes 1B, 1C, and 1D are measured.

  Next, based on the measured voltage and current, the combined resistance between A-B, A-C, and A-D is calculated (step S8).

  Next, it is determined whether or not the calculated combined resistance value R is greater than or equal to a standard value (step S9). If it is determined that the combined resistance value R is greater than or equal to the standard value, it is determined that all the nets are good because sufficient insulation resistance is maintained (step S10).

  When it is determined that the combined resistance value R is smaller than the standard value, the process proceeds to step S3 and measurement is performed at 1: 1. While switching the switch unit 3, the three SW 1 to 3 are sequentially turned on and inspected 1: 1 to identify the defective part. Specifically, the three switchable movable probes 1B, 1C, and 1D are short-circuited one by one by sequentially turning on the three SW1 to SW3 for the direct-coupled movable probe 1A. The insulation resistance between the nets is inspected 1: 1 to identify the abnormal part.

  Next, it is determined whether or not all inspections have been completed (step S11), and if not completed, the process returns to step S1 and the above processing is repeated. If it is determined that all the inspections have been completed, each movable probe 1A, 1B, 1C, 1D is moved to the home position (step S12).

  The movable contact inspection apparatus of this embodiment has the following effects by operating as described above.

  In the conventional inspection method using a flying prober, as described above with reference to FIG. 2, when measuring the insulation resistance between the nets A, B, C, and D, two movable probes are brought into contact with the two nets to be measured. Since the insulation resistance was measured, when the target net was n sets, the inspection had to be performed n times, and the inspection efficiency was poor. There is also an invention of Patent Document 1 in which a plurality of nets are inspected sequentially by a switch circuit during measurement to shorten the inspection time, but the inspection time is not significantly reduced. In particular, due to the increase in the number of nets accompanying the recent increase in density, the inspection time has increased and the inspection efficiency has deteriorated.

  On the other hand, the inspection method of this embodiment measures a plurality of wirings simultaneously for a plurality of nets A, B, C, D as shown in FIG. When n movable probes 1 are provided, a maximum of n-1 nets are simultaneously measured for one net A serving as a reference. Here, since four movable probes 1A, 1B, 1C and 1D are provided, three nets B, C and D are measured simultaneously. When five or more movable probes 1 are provided and five or more nets are measured, four or more nets are measured simultaneously except for the direct-coupled movable probe 1A.

  Thereby, the inspection time can be greatly shortened. As a result, the inspection efficiency can be greatly improved.

[Modification]
In the embodiment, the case where the number of the movable probes 1 of the movable contact inspection apparatus is four has been described as an example, but may be three or five or more. Although it depends on the size of the inspection device, etc., inspection is performed using the same number of movable probes 1 as the number of nets to be inspected.

  When the number of movable probes 1 is smaller than the number of inspection target nets, the following inspection method can be used. For example, if there are 10 inspection target nets and 4 movable probes 1, the four movable probes 1 simultaneously form four nets, such as nets 1 to 4, 5 to 8, and 7 to 10. Make contact and inspect the last part with slack. When there are 10 inspection target nets and 6 movable probes 1, the numbers are 1 to 6, 5 to 10. According to the number of movable probes 1, the inspection target net is divided into two or three or more and inspected.

  In the above embodiment, the insulation resistance is described as an example of the electrical characteristic to be measured, but it goes without saying that other electrical characteristics may be used.

It is a functional block diagram showing a schematic structure of a movable contact inspection device (flying prober) according to an embodiment of the present invention. It is a schematic diagram which shows the example of the inspection method by the conventional flying prober. It is a timing chart which shows the processing function in the control device concerning the embodiment of the present invention. It is a circuit diagram which shows the operation example of the switch part which concerns on embodiment of this invention. It is a circuit diagram which shows the operation example of the switch part which concerns on embodiment of this invention. It is a flowchart which shows the specific process function of the control apparatus which concerns on embodiment of this invention. It is a schematic diagram which shows the example of the test | inspection method by the flying prober which concerns on embodiment of this invention.

Explanation of symbols

  1: movable probe, 2: XYZ drive unit, 3: switch unit, 4: control device, 6: net, 8: switch switching control unit, 9: XYZ axis drive control unit, 10: display unit, 11: R calculation pass / fail Determination unit, 12: insulation resistance input / output unit.

Claims (3)

A movable contact inspection apparatus that has a plurality of movable probes and measures electrical characteristics at a plurality of locations of an inspection object,
The plurality of movable probes comprises at least one direct-coupled movable probe and another switchable movable probe,
An XYZ driving unit that supports each movable probe and accurately positions and contacts the inspection object;
A switch unit that electrically short-circuits and selectively connects the plurality of switchable movable probes;
Expected to be a composite value of the electrical characteristics detected by each of the switching type movable probes that are brought into contact with the direct connection type movable probe and the switching type movable probe simultaneously at a plurality of locations of the inspection object and short-circuited via the switch unit. A movable contact comprising: a control device that judges that an abnormality occurs when the value deviates from the value, controls the switch unit, selectively connects each movable probe, and identifies an abnormal location Inspection device. In the movable contact inspection apparatus according to claim 1,
When the control device determines that the combined value of the electrical characteristics deviates from the expected value and is abnormal, the switch unit is controlled to connect each of the movable probes one by one to identify the abnormal location. Movable contact inspection device. In the movable contact inspection apparatus according to claim 1,
When it is determined that the combined value of the electrical characteristics is out of the expected value in the control device and is abnormal, the switch unit is controlled to connect each of the plurality of movable probes to roughly identify the abnormal part, After that, the movable contact inspection apparatus is characterized in that the abnormal part is specified by gradually narrowing the range for specifying the abnormal part.

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